Influence of Chemical Effect on the Kβ/Kα Intensity Ratios and Kβ Energy Shift of Co, Ni, Cu, and Zn Complexes

Chemical effects on the Kβ/Kα intensity ratios and △E energy differences for Co, Ni, Cu, and Zn complexes were investigated. The samples were excited by 59.5 keV γ-rays from a ^241Am annular radioactive source. K X-rays emitted by samples were counted by an Ultra-LEGe detector with a resolution of 150 eV at 5.9 keV. We observed the effects of different ligands on the Kβ/Kα intensity ratios and △E energy differences for Co, Ni, Cu, and Zn complexes. We tried to investigate chemical effects on central atoms using the behaviors of different ligands in these complexes. The experimental values of Kβ/Kα were compared with the theoretical and other experimental values of pure Co, Ni, Cu, and Zn.

P-Δ effect on inelastic displacement ratio spectra for inelastic structures

For the evaluation of structures with known ductility demands,the constant-ductility displacement ratio spectra(CDDRS) are particularly useful for providing inelastic displacement ratios to estimate maximum lateral inelastic displacement demands from maximum elastic displacement demands.The CDDRS are computed for single-degree-of-freedom systems(SDOF) by considering or ignoring P-Δ effect for different ductility levels when subjected to 344 earthquake ground motions recorded in four site classes.The modified expressions of CDDRS for P-Δ effect are proposed.It is concluded that the P-Δ effect on CDDRS is significant,and the effect increases with the increase of ductility level.In the long-period region,the CDDRS ignoring P-Δ effect almost conforms to the equal-displacement rule.But in the case of higher ductility level,the CDDRS considering P-Δ effect are much higher than 1.0,which do not conform to the equal-displacement rule.

The Inhibitory Degree Between Skeletonema costatum and Dinoflagllate Prorocentrum donghaiense at Different Concentrations of Phosphate and Nitrate/Phosphate Ratios

Interactions between Skeletonema costatum (S. costatum) and Prorocentrum donghaiense (P. donghaiiense) were inves-tigated using bi-algal cultures at different concentrations of phosphate (PO4-P) and nitrate/phosphate (N/P) ratios. Experiments were conducted under P-limited conditions and the Lotka-Volterra mathematical model was used to simulate the growth of S. costatum and P. donghaiense in the bi-algal cultures. Both of these two species were inhibited significantly in bi-algal culture. The results of the simulation showed that the inhibitory degree of S. costaum by P. donghaiense was high when the concentration of PO4-P was low (0.1μmolL-1/2 d), but that of P. donghaiense by S. costaum was high with increased PO4-P supply (0.6μmolL-1/2 d). At low concen-tration of PO4-P (0.1μmolL-1/2 d), or high concentration of PO4-P (0.6μmolL-1/2 d) with high N/P ratio (160), the interactions be-tween S. costatum and P. donghaiense were dependent on the initial cell densities of both species. At high concentration of PO4-P (0.6μmolL-1/2 d) with low N/P ratio (25 or 80), S. costatum exhibited a survival strategy superior to that of P. donghaiense. The de-gree of inhibition of P. donghaiense by S. costaum increased with elevated N/P ratio when the medium was supplemented with con-centration 0.1μmolL-1/2 d of PO4-P. The degree of inhibition to P. donghaiense by S. costaum increased with elevated N/P ratio at low concentration of PO4-P (0.1 μmolL-1/2 d). This trend was conversed at high concentration of PO4-P (0.6μmolL-1/2 d). However, the degree of inhibition of S. costaum by P. donghaiense increased with the increased N/P ratio at different PO4-P concentrations (0.1μmolL-1/2 d and 0.6μmolL-1/2 d). These results suggested that both phosphate concentration and N/P ratio affected the competition between S. costaum and P. donghaiense: P. donghaiense is more competitive in environments with low phosphate or high N/P ratio and the influence of N/P ratio on the competition was more significant with lower phosphate concentration.

Hepatic Protective Effects of <i>S</i>-Allyl-L-Cysteine (SAC) in Rats with Carbon Tetrachloride (CCl₄) Induced Liver Injury

S-allyl-L-cysteine (SAC) is an organosulfur compound derived from aged garlic extract (AGE). Studies have reported that AGE possesses bioprotective capacity, including antidiabetic, antimicrobial, antioxidant, and antitumor effects. The present study examined the protective effects of SAC against carbon tetrachloride (CCl4) induced hepatotoxicity in rats. Ten male Wistar rats aged 11 - 12 weeks were randomly divided into two groups (five rats/group) as control and SAC groups. All rats had ad libitum access to water, and the SAC group received water containing SAC intragastrically (200 mg/kg) once daily for five consecutive weeks. In the fifth experimental week, 50% CCl4 in olive oil (1 mL/kg) was administered intraperitoneally three times a week to induce liver injury in both groups. Rats were sacrificed at 24 hours after the last CCl4 injection, and liver tissues were excised for histopathological, immunohistochemical and antioxidant analyses. The rats in the SAC group did not show abnormal behavior, such as decreased water intake or food consumption, during the experimental period. Body weights in all groups did not change significantly over the experimental period. Histopathological analysis showed that the percentage of hepatic steatosis was lower in the SAC group at 12.75% ± 3.74% compared to 24.64% ± 5.29% in the control group (p < 0.05). The percentage of cytochrome P4502E1 (CYP2E1) distribution area in the SAC group was also lower at 19.61% ± 6.18% compared with 25.22% ± 6.21% in the control group (p < 0.05). These results suggest that SAC can alleviate CCl4-induced liver damage by decreasing hepatic steatosis and reducing CYP2E1 expression in rats.

弹丸转速对PELE侵彻钢筋混凝土靶横向效应的影响

为了研究弹丸转速对横向效应增强型侵彻体(PELE)侵彻钢筋混凝土靶横向效应的影响,运用ANSYS/LS-DYNA软件在着靶速度600、700和800m/s条件下,对具有不同转速的PELE侵彻钢筋混凝土靶进行数值模拟,并通过试验方法对不同着靶条件下的仿真模型进行验证。结果表明,开孔尺寸的数值模拟结果与实验结果之间的误差小于5%,仿真模型能够准确模拟PELE侵彻钢筋混凝土靶的过程;随着转速的不断提高,损失更多的转速动能转化为钢筋混凝土靶开孔破坏所需的能量,使钢筋混凝土靶的开孔尺寸增大;在同一着靶速度下,转速从10 000r/min提高至25 000r/min,开孔尺寸提高了约(8±2)%。因此,在同一着靶速度下,增加弹丸转速有利于提高PELE对钢筋混凝土靶的开孔尺寸。

氧化铝生产综合能耗的e^-_p分析

在推演氧化铝生产综合能耗基本计算式的基础上 ,提出了氧化铝生产企业剖析综合能耗的e p分析法。并以某氧化铝厂 1995～ 2 0 0 0年的生产和能源消耗统计数据为依据 ,分析了工序能耗变化和折合比变化对综合能耗的影响。认为为了降低氧化铝生产综合能耗 ,一是要降低各工序的折合比 ,二要降低各工序能耗。并指出为了降低各工序的折合比 ,需要优化生产工艺结构 ,加大拜耳法及拜耳法中管道化的比例 ,通过选矿法来提高矿石的品位。

心电图P/P-R段与二尖瓣频谱E/A评价左室舒张功能比较与探讨

目的 评价心电图 P波 / P- R段比值和二尖瓣血流频谱 E/ A比值诊断左室舒张功能(L VDF)异常的价值。方法 测量 89例高血压病、冠心病、心肌梗塞等患者的心电图 P/ P- R比值及多普勒超声心动图二尖瓣频谱 E/ A比值 ,并与 76例正常人对比分析。结果 P/ P- R比值诊断 L VDF异常的敏感性高于 E/ A比值 ,特异性及准确性无显著差别。结论 P/ P- R>1.6可提示 L VDF异常。

冠心病心绞痛患者QTd、T_(p)-T_(e)间期、T_(p)-T_(e)/QT比值、HRV变化及其与冠脉病变程度的关系

目的探究冠心病(CHD)心绞痛患者QT离散度(QTd)、T波峰-末(T_(p)-T_(e))间期、T_(p)-T_(e)/QT比值、心率变异性(HRV)水平变化及其与冠脉病变严重程度的关系。方法选择2018年8月至2021年10月在宝鸡市人民医院就诊的98例CHD心绞痛患者作为研究组,根据冠脉病变程度分为轻度组34例、中度组40例和重度组24例,选择同期来我院检查的非CHD心绞痛患者60例作为对照组。CHD心绞痛患者均经PCI治疗,收集两组患者的一般资料,比较对照组和研究组患者PCI手术前后的QTd、T_(p)-T_(e)间期、T_(p)-T_(e)/QT比值、HRV及心肌肌钙蛋白I(cTnI)、肌酸激酶同工酶(CK-MB)水平,采用Pearson相关性分析心电指标与术前心肌酶谱指标及冠脉病变严重程度的关系。结果研究组患者术前的cTnI、CK-MB、QTd、T_(p)-T_(e)间期以及T_(p)-T_(e)/QT比值水平明显高于对照组,术后的cTnI、CK-MB、QTd、T_(p)-T_(e)间期以及T_(p)-T_(e)/QT比值虽然明显低于其术前,但仍明显高于对照组,差异均有统计学意义(P<0.05);研究组患者术前的HRV各参数水平明显低于对照组,术后,研究组患者的HRV各参数水平虽然明显高于其术前,但仍明显低于对照组,差异均有统计学意义(P<0.05);术后,三组不同冠脉病变程度患者的QTd、T_(p)-T_(e)间期、T_(p)-T_(e)/QT比值随着冠脉病变程度的增加而升高,HRV各参数水平随着冠脉病变程度的增加而降低,差异均有统计学意义(P<0.05);经Pearson相关性分析结果显示,QTd、T_(p)-T_(e)间期、T_(p)-T_(e)/QT比值与cTnI、CK-MB水平、冠脉病变严重程度均呈正相关(P<0.05),HRV各参数与cTnI、CK-MB水平、冠脉病变严重程度均呈负相关(P<0.05)。结论CHD心绞痛患者的心肌酶谱、QTd、T_(p)-T_(e)间期、T_(p)-T_(e)/QT比值及HRV各参数水平均出现异常,CHD心绞痛患者PCI术后的各心电指标与患者术前心肌损伤、冠脉病变严重程度均相关。

Dietary lipid and gross energy affect protein utilization in the rare minnow Gobiocypris rarus

An 8-week feeding trial was conducted to detect the optimal dietary protein and energy, as well as the ef fects of protein to energy ratio on growth, for the rare minnow( Gobiocypris rarus), which are critical to nutrition standardization for model fi sh. Twenty-four diets were formulated to contain three gross energy(10, 12.5, 15 kJ/g), four protein(20%, 25%, 30%, 35%), and two lipid levels(3%, 6%). The results showed that optimal dietary E/P was 41.7–50 kJ/g for maximum growth in juvenile rare minnows at 6% dietary crude lipid. At 3% dietary lipid, specifi c growth rate(SGR) increased markedly when E/P decreased from 62.5 kJ/g to 35.7 kJ/g and gross energy was 12.5 kJ/g, and from 75 kJ/g to 42.9 kJ/g when gross energy was 15.0 kJ/g. The optimal gross energy was estimated at 12.5 kJ /g and excess energy decreased food intake and growth. Dietary lipid exhibited an apparent protein-sparing eff ect. Optimal protein decreased from 35% to 25%–30% with an increase in dietary lipid from 3% to 6% without adversely ef fecting growth. Dietary lipid level af fects the optimal dietary E/P ratio. In conclusion, recommended dietary protein and energy for rare minnow are 20%–35% and 10–12.5 k J/g, respectively.

The Limitations of Polygenic Hypothesis and Theorizing about Dual Multiple Factors and Three Normal Distributions

The original data of Nilsson-Ehle experiment in wheat were analyzed with existent genetic knowledge. It indicated that the core of polygenic hypothesis from this experiment was that a character similarity produced by additive effect of multiple genes was the basis of continuous variation. Its precondition was for effective genes to have equal effect, to show merodominance and binomial distribution and to inherit independently. In fact, quantitative characters were determined by many genes with different property, effect and behavior. So it was difficult to solve all problems of continuous variation by the aid of polygenic hypothesis. The researchers should seek new ways. With Mendelian group as research object and by means of Lyapunov central limit theorem it was proved that both genotypic value G and the environmental effect in a niche E were subordinated to the normal distribution and respectively. According to additivity of the normal distribution the phenotype P = G + E also obeyed the normal distribution P = G + E ~ and quantitative characters showed continuous variation, whether or not the linkage was presented, whether or not every gene effect was equal, whether or not there were dominance and what kind of dominance between alleles. Moreover it was discussed that the quantitative characters in self-fertilized organism and clone were submitted to the normal distribution and presented continuous variation too.

NAND flash service lifetime estimate with recovery effect and retention time relaxation

A service life model of NAND flash and threshold voltage shift process is proposed to calculate the service life and endurance.The relationships among achievable program/erase(P/E) cycles,recovery time,bad block rate and storage time are analyzed.The achievable endurance and service life of a NAND flash are evaluated based on a flash cell degradation and recovery model by varying recovery time,badblock rate,and storage time.It is proposed to improve the service lifetime of solid state disk by both relaxing the bad block rate limitation and retention time while extending the recovery time.The results indicate that endurance can be improved by 17 times if the storage time guarantee is reduced from 10 a to 1 a with 105 s recovery time inserted between cycles.

发行市盈率管制的溢出效应研究——基于IPO抑价与溢价的视角

注册制前IPO定价多受到发行市盈率管制约束,随着注册制的实施该管制被全面放开。现有相关研究大都关注于高发行市盈率公司,鲜有学者注意该管制对低发行市盈率公司的影响。以注册制实施前主板与创业板低发行市盈率IPO公司为样本,从IPO抑价与溢价影响视角对发行市盈率管制潜在负面经济后果进行探讨。采用OLS方法,发现市盈率管制存在溢出效应,市盈率管制期间未受到直接限制的低发行市盈率公司IPO定价更低即存在抑价,上市后股价更高即存在溢价;市盈率管制期间,低发行市盈率公司短期、中期和长期市场表现弱于非市盈率管制期间;市盈率管制对低发行市盈率公司IPO抑价程度的影响在融资约束较强产权性质为国企时较弱。研究结果表明市盈率管制导致IPO定价与上市后的股价更大程度偏离内在价值,表明该管制政策存在较大负面效应,取消发行市盈率管制具有合理性,同时提示该管制取消后应警惕IPO定价过高带来的新股破发问题。

股票市盈率波动有偏性对投资者股票交易量的影响研究--基于沪深300指数

有着独特波动规律的股票市盈率,会对投资者的股票交易产生影响。从市盈率波动有偏性的角度出发,以沪深300指数的市盈率数据为研究样本,构建回归模型,实证检验市盈率波动有偏性对股票交易量的影响,结果表明:沪深300指数市盈率波动相对于正常波动水平存在明显右偏性;沪深300指数市盈率波动的持续时间较长且具有非对称性;沪深300指数市盈率波动右偏性对股票成交量具有显著的反向影响,并且这种影响受到经济增长、出口量、利率、汇率、居民消费价格指数和货币供应量的非对称约束。要稳定股市交易量,就需要综合考虑上述因素的影响,并根据市场变动灵活调整政策措施。

考虑P-△效应的桥梁结构震后概率残余位移分析

残余位移是评价桥梁结构震后可修复性和可用性的重要指标,而P-△效应对桥梁结构的残余位移影响显著。综合考虑P-△效应和地震动随机特性的影响,通过大量的非弹性动力时程分析,定量地分析桥梁结构震后残余位移的概率统计特征和经验预测方程。首先根据动力平衡原理,建立考虑P-△效应的桥梁结构非弹性地震动力响应分析的运动控制微分方程,然后结合所筛选的69条强震记录,利用概率统计方法定量地分析P-△效应、屈服后刚度比、规一化屈服强度和自振周期等因素对震后残余位移的概率统计特征的影响,进而对残余位移与峰值位移之间的相关性进行讨论,并建立残余位移与峰值位移之间的经验预测方程。分析结果表明:P-△效应、屈服后刚度比和规一化屈服强度对残余位移的均值影响较大,而对残余位移的变异性影响相对较小;桥梁结构的震后残余位移可以描述为对数正态分布或威布尔分布随机变量;残余位移与峰值位移之间具有较强的相关性,且二者比值的均值(变异系数)随着自振周期和稳定系数的增大而增大(减小)。

考虑P-Δ效应的等延性位移比谱

应用等延性位移比谱可以简便有效地估计结构的非弹性位移.在地震动作用下,由于P-Δ效应能够增加结构的非弹性变形和永久变形,因此,研究P-Δ效应对等延性位移比谱的影响具有重要意义.利用四类场地上的344条地震动,分别计算出了考虑及未考虑P-Δ效应的等延性位移比谱,并进行了对比分析,然后根据统计分析的结果,得到了等延性位移比谱考虑P-Δ效应的修正公式.结果表明:P-Δ效应对等延性位移比谱的影响十分可观,并且其影响程度随结构延性的增加而增大,随结构周期的增加而减小;而且当考虑P-Δ效应之后,等位移原理不再适用.

基于动态功率阈值降低PAPR的部分传输序列算法

为了改善正交频分复用(orthogonal frequency division multiplexing,OFDM)系统的峰均功率比(peak-to-average power ratio,PAPR)性能,提出了一种基于动态功率阈值的低复杂度部分传输序列(partial transmit sequences,PTS)方法。在新的PTS方法中,引入了基于功率的判别函数,并给出了一种基于功率合理选择阈值的方法。在选取最小的PAPR值进行传输时,只对Pn大于等于阈值的样本信号进行峰值功率的计算。与传统的PTS算法相比,本文提出的算法在保证PAPR性能和误码率的情况下,能够更有效地降低计算复杂度。

首次公开发行股票(IPO)定价模型的评析

对首次公开发行股票定价的三种模型的假设条件、应用优势和局限性进行了评估。

IPO新股询价制对电力行业股票收益率的影响

应用数理统计并结合金融数学的方法,研究不同的新股发行方式对电力行业上市公司的影响,实证研究IPO询价制度实行前后电力行业的股票市盈率及股票收益率的变化趋势和特点,研究市盈率和收益率的统计分布及相关模型.首次尝试采用稳健的R估计法建立电力行业股票收益率与经营业绩指标的数学模型.

乙烯原料最适裂解温度研究

采用裂解炉标定方法,探究气体、石脑油、加氢尾油三种原料在不同裂解温度下的产品分布,选取最佳经济效益点,同时考虑高附产品收率相对较好,兼顾对应温度下裂解炉运行周期,得出最适宜温度。经数据分析,在以经济效益最大化为前提,兼顾高附收率以及运行周期条件下,确定1^(#)裂解炉裂解气体最佳温度在860℃;6^(#)裂解炉裂解加氢尾油最佳温度在810℃,此时丙/乙比0.6;确定7^(#)裂解炉裂解石脑油最佳温度在845℃,此时丙/乙比0.56。

广义p值与多元随机效应模型的精确检验

在多元随机效应模型中,一般采用似然比检验或者其他近似方法检验关于回归系数矩阵的统计假设.这些方法都不是精确的检验.为了得到一种精确的检验,方法是把广义p值应用到多元随机效应模型中.模拟结果显示,在小样本情况下,广义检验可以控制检验水平,且比似然比方法有更好的检验效果.